Empirical and Molecular Formulas

Front

What is an empirical formula?

Back

An empirical formula represents the simplest whole-number ratio of atoms of each element in a compound.

Front

What is a molecular formula?

Back

A molecular formula shows the actual number and kinds of atoms present in one molecule of a compound.

Front

How do you determine the empirical formula from percent composition?

Back

Convert the percentage of each element to grams, then to moles, and find the simplest whole-number ratio.

Front

Given the empirical formula CF2 and a molecular formula mass of 200.94 g/mol, what is the molecular formula?

Back

C4F8.

Front

Which pair has the same empirical formula: NaCrO4 and Na2Cr2O7, or C2H4O2 and C6H12O6?

Back

C2H4O2 and C6H12O6.

Front

What is the empirical formula of a compound with 15.8% carbon and 84.2% sulfur?

Back

CS2.

Front

If the empirical formula is CH2O and the molar mass is 180 g/mol, what is the molecular formula?

Back

C6H12O6.

Front

What is the difference between empirical and molecular formulas?

Back

Empirical formulas show the simplest ratio of elements, while molecular formulas show the actual number of atoms.

Front

How do you calculate the molar mass of a compound?

Back

Add the atomic masses of all atoms in the molecular formula.

Front

What is the empirical formula for C3H6O3?

Back

C1H2O1 or CH2O.